Relationship between Theileria parva entomological inoculation rate and prevalence in three agroecological zones of the democratic republic of Congo

Description

Theileria parva is a protozoan parasite which causes East Coast fever (ECF), a lethal lympho-proliferative disease of cattle. ECF kills over 1 million cattle/year with economic losses of ~USD300 million in eastern, central and southern Africa.

The study was curried out to assess the prevalence of T. parva in the bovine host as well as in pooled free-living Rhipicephalus appendiculatus tick vectors by nested-PCR based on three antigens genes (p104, Tp1 and Tp2) and to estimate the entomological inoculation rate (EIR). Three cross-sectional studies was conducted in three different seasons (two wet seasons and one dry season) and three agroecological zones (AEZ) namely low, medium and high altitude of the Democratic Republic of Congo. The farms were selected by first stratifying the study area by AEZ and implementing a random sampling in administrative localities. A total of 1230 blood samples and 6060 ticks were collected from cattle and 1740 ticks from pasture.

The overall prevalence of T. parva in cattle was respectively 56%, with Variations observed between AEZ and seasons. R. appendiculatus was the most abundant tick specie with a burden of 26 ticks/animal corresponding to 71.5% of the tick load. The tick burden was higher in low and intermediate altitude lands than highlands. The overall T. parva prevalence in pooled free-living R. appendiculatus and the mean EIR was 16.7 % and 13.3 % respectively. The prevalence was higher in the lowland and intermediate altitude than high altitude. Prevalence of infection in cattle and ticks and tick infestation levels were analysed for association with seasonal and agroecological factors.

The results on R. appendiculatus abundance, T. parva prevalence and calculating entomological inoculation rate at different places and times should have important implication in the selection of the most appropriate T. parva control strategies and integrated vector management in the region.

Période	20 mai 2016
Conservé à	Belgian Society of Parasitology & Protistology (BSPP), Belgique
Niveau de reconnaissance	International